thoracic wall exam 3 anatomy Flashcards
what is included in the thoracic skeleton?
12 thoracic vertebrae and IV discs
12 pair of ribs
costal cartilages
sternum
describe the throracic articular facets (position and function)
they face anteriorly/posteriorly
rotation
some lateral flexion
which part of the rib is most susceptible to a fracture?
angle of the rib
what part of ribs protects neurovascular supply?
costal groove
what are the 2 atypical ribs?
rib 1
rib 12- floating, not directly attached to costal cartilage
what kind of cartilage and joints are the costal cartilages?
-hyaline cartilage
-sternocostal joints (mostly synovial)
what structures are palpable at the costal margin?
liver, xyphoid process, gallbladder, maybe a part of the stomach
rib classification
true ribs= 1-7
false ribs= 8-10
floating ribs= 11-12
rib 2 is involved with what 2 structures of the sternum?
half is w body of sternum and half is w manubirum
what joint is the base of the heart at?
xiphisternal joint
what anatomical structures are located at sternal angle?
aortic arch, bifercation of trachea
what cartilages are at body of sternum?
what procedures are associated with body of sternum?
-costal cartilages 2-7
-sternal biopsy, median sternotomy, sternal rub
what part of the sternum can potentially break off and go into the liver?
xiphoid process
xiphoid process
-ossifies about 40 years old
-t10 vertebral level
-diaphragm attachment
-xiphisternal joint
movements of the thoracic wall
sternum- pendulum movement
ribs- bucket handle mvmt
muscles of the thoracic wall
pectoralis major, pectoralis minor, serratus anterior, transverse thoracis, intercostal muscles
pectoralis major
origin, action, insertion
-2 heads (clavicular head and sternocostal head)
-insertion= lateral lip of intertubecular groove of humerus
-action=
*adduct and medially rotate humerus
*draws scapula anterior and inferiorly
-isolated action=
*clavicular head flex humerus
*sternocostal head extend humerus
innervation of pectoralis major
medial and lateral pectoral nerves *these are branches of the brachial plexus
pectoralis minor origin, action, insertion
origin=ribs 3-5
action=stabilize scapula
insertion=coracoid process
innervation of pectoralis minor
medial pectoral nerve
“medial does more”
origin, action, and insertion of serratus anterior
origin=ribs 1-8/9 and side of chest
action=draws scapula anterior and superior; abducts scapula; scapular rotation and stabilization of vertebral border
insertion= long thoracic nerve
origin, action, and insertion of transversus thoracis
origin=costal cartilages of last 3-4 ribs
action=depresses ribs
insertion=ribs and costal cartilages of 2-6
what is the innervation of transversus thoracis
intercostal nerves
what is the function and innervation of the intercostal muscles?
function= stabilize intercostal spaces during respiration
innervation= intercostal nerves
layers of the intercostal muscles
external-elevate ribs during forceful inspiration
internal-depresses ribs during forced expiration
innermost-reduce transverse dimension of thoracic cavity during expiration
where are the intercostal nerves coming from?
ventral rami
where are the intercostal arteries coming from?
aorta
where do intercostal veins drain?
azygos system
subcostal nerve
T12
intercostal nerve fibers
*somatic motor
*somatic sensory fibers
*sympathetic fibers
somatic motor- intercostal muscles
somatic sensory-from skin to thoracic wall
sympathetic-to sweat glands, arrector pili muscles, blood vessels in skin
what are the sympathetic targets in the skin?
blood vessels, arrector pili, sweat glands
somatic sensory pathway in thoracic wall
starts in lateral horn
then proceeds to ventral root>spinal nerve>ventral ramus>white ramus comm>sympathetic trunk
synapses in paravertebral ganglia
then goes to gray ramus comm and ventral or dorsal rami
ends at body
thoracic wall blood supply
thoracic aorta and internal thoracic arteries
thoracic wall venous drainage
posterior intercostal veins and anterior intercostal veins
thoracotomy
incision through thoracic wall to enter pleural cavity
rib retraction
allows procedures performed via single intercostal space
median sternotomy
wide access to thoracic cavity (crack chest)
thoracic outlet syndrome
-compression of structures exiting the superior thoracic aperture
-costoclavicular syndrom
